The invention relates to means for lubricating the bearings of a marine propulsion device, and, more particularly, to means for lubricating the bearings supporting the vertical drive shaft of a marine propulsion device.
It is known to use an Archimedean screw on the outside of the vertical drive shaft of a marine propulsion device in order to pump lubricant upwardly to the upper bearings supporting the drive shaft. See, for example, Holtermann U.S. Pat. No. 3,645,360 and FitzGerald U.S. Pat. No. 1,822,573.
Also, Becker U.S. Pat. No. 3,799,291 discloses a vertical drive shaft having therein an axial bore and radial apertures for supplying lubricant to the upper gearcase.
Attention is also directed to the following U.S. patents:
Shively: 2,569,346, Sept. 25, 1951 PA0 Shively: 2,691,954, Oct. 19, 1954 PA0 Ayling: 2,963,113, Dec. 6, 1960 PA0 Ellzey: 3,428,018, Feb. 18, 1969 PA0 Ellzey: 3,520,272, July 14, 1970 PA0 Shimanckas: 3,608,684, Sept. 28, 1971 PA0 Croisant: 3,931,783, Jan. 13, 1976 PA0 Schiek: 4,650,430, Mar. 17, 1987